Scheduled server cleanups

As it is no longer bearable to play on this world anymore (restart once per hour required), I decided to schedule abandoned grid cleanups once a week. That means, that every unclaimed structures will be removed.

The plan is to block the server for one hour per week and set the abandoned grid cleaner to 1 hour (apparently that's the minimum), so it can delete all abandoned, respectively unclaimed grids. The mechanic to "visit" unclaimed structures to reset the timer won't apply during this cleanup because the server is going to run 1+ hour to make it work.
Since there is still a bug, that prevents house members to pay for a friend's claimblock, everyone has to take care of their claimblocks for themselves.
After the cleanup is done, we will go back to the usual timer: 3 days

Important: If you need someone to look after your claimblocks because you are in vacation etc. contact an admin and tell him the exact coordinates of the area(s), so he can take care of it!